Re: 500W alternator stator (again)
Posted: 03 Jan 2023 12:06
Hi all,
Just a follow-up on the re-wound stator saga. I finally ended up with 50 turns of 0.8mm wire on each coil. It was just too difficult to wind that many turns of 1.0mm wire by hand on the short bobbins. I think a professional with a coil winding machine could do it, but the wire is too thick and too stiff to do it by hand. I did the winding with the plastic bobbins in place and using a single continuous length of wire, reversing the direction of winding after each coil. This is by far the easiest way to do it by hand, in fact the whole winding operation only takes about 15 minutes.
Anyway, this arrangement gave a much better cut-in rpm and with lights on, the alternator would maintain 14.4 battery volts from around 2500 rpm. I didn't have time to do any proper load test because by then I was just a few days away from leaving for the Moto Piston Rally. Still, the bike was running well, the lights were bright and I'd even fitted in a 10 mile shake-down test. What could possibly go wrong?
In fact nothing did go wrong. I covered about 1300 miles on the rally as usual, the Sachse ignition was brilliant, the electrics gave no trouble at all and much fun was had.
So what's the conclusion? Well this re-wind is a practical proposition if your stator is in a bad way as mine was. If I had time, I would probably use a professional coil-winding service and go for 1.0mm wire, but 0.8mm works fine and bends a lot more easily! If I get around to it (probably not!) I might do a load test just so that I know how many watts I have to play with, but the experience of the 2022 Piston Rally is that it is adequate anyway.
Now on to the clutch problems....!
Joe.
Just a follow-up on the re-wound stator saga. I finally ended up with 50 turns of 0.8mm wire on each coil. It was just too difficult to wind that many turns of 1.0mm wire by hand on the short bobbins. I think a professional with a coil winding machine could do it, but the wire is too thick and too stiff to do it by hand. I did the winding with the plastic bobbins in place and using a single continuous length of wire, reversing the direction of winding after each coil. This is by far the easiest way to do it by hand, in fact the whole winding operation only takes about 15 minutes.
Anyway, this arrangement gave a much better cut-in rpm and with lights on, the alternator would maintain 14.4 battery volts from around 2500 rpm. I didn't have time to do any proper load test because by then I was just a few days away from leaving for the Moto Piston Rally. Still, the bike was running well, the lights were bright and I'd even fitted in a 10 mile shake-down test. What could possibly go wrong?
In fact nothing did go wrong. I covered about 1300 miles on the rally as usual, the Sachse ignition was brilliant, the electrics gave no trouble at all and much fun was had.
So what's the conclusion? Well this re-wind is a practical proposition if your stator is in a bad way as mine was. If I had time, I would probably use a professional coil-winding service and go for 1.0mm wire, but 0.8mm works fine and bends a lot more easily! If I get around to it (probably not!) I might do a load test just so that I know how many watts I have to play with, but the experience of the 2022 Piston Rally is that it is adequate anyway.
Now on to the clutch problems....!
Joe.